I agree with Tim's assessment. In my case I do though, as my signature says, happen to have BOTH. I use both devices however in very different ways which gets into a lot of what Tim was saying. But I like that the apps can go on both, as can the books. If I am waiting in a doctor office and am reading a book and don't feel like bringing my iPad in, I use my iPhone just for that time as since it's my phone, it is with me anyway. I will go back and forth and play a word game with it as I tire of reading on the small screen, so I might quickly glance at a news story; a phone is easier to hold in the hand in a waiting room. At home before bed, I am using the iPad to read e-books and surf the net, write on PDFs, etc. Sometimes I will play a few games too, all depends. But it's funny because I thought since it's the same OS I would just use them the same way, and I really don't.